1. Field of the Invention
This invention pertains to the field of 2-haloacetanilides and their use in the agronomic arts, e.g., as herbicides.
2. Description of the Prior Art
The prior art relevant to this invention includes numerous disclosures of 2-haloacetanilides which may be unsubstituted or substituted with a wide variety of substituents on the anilide nitrogen atom and on the anilide ring including alkyl, alkoxy, alkoxyalkyl, halogen, etc., radicals.
As relevant to the invention compounds, which are characterized by having an alkoxymethyl or alkenyloxymethyl radical on the anilide nitrogen, an alkoxy radical in one ortho position and a specific alkyl radical in the other ortho position, the closest prior art known to the inventor are U.S. Pat. Nos. 3,442,945 and 3,547,620. The most relevant disclosures in the '945 and '620 patents are the compounds 2'-tert-butyl-2-chloro-N-methoxymethyl-6'-methoxyacetanilide and its bromo analog (Examples 18 and 34 of the '620 patent and Examples 18 and 36 of the '945 patent, respectively).
U.S. Pat. Nos. 4,070,389 and 4,152,137 disclose generic formulae which encompass compounds of the type disclosed in said '945 and '620 patents. However, the only disclosed species compound having an alkyl radical in one ortho position and an alkoxy radical in the other ortho position has an alkoxyethyl radical on the anilide nitrogen atom; compounds of this type are discussed in more detail below.
Other less-relevant prior art are Belgian Pat. No. 810,763 and German Application No. 2,402,983; the compounds of these references include compounds of the type disclosed in said '389 and '137 patents and are characterized by an alkoxyalkyl radical having two or more carbon atoms between the anilide nitrogen atom and the oxygen atom of the alkoxy moiety. The most relevant specific disclosures in said Belgian '763 patent and German '983 application appear to be compounds having an ethoxyethyl radical on the anilide nitrogen atom, a methoxy or ethoxy radical in one ortho position and a methyl, ethyl or isopropyl radical in the other ortho position; referring to the '763 patent, see Compound Numbers 7, 13, 18-20 and 26; other less-relevant homologs of these compounds are also disclosed, e.g., Compounds 6, 9, 16 and 17, which have methoxyethyl or methoxypropyl radicals substituted on the nitrogen atom and a methoxy or ethoxy radical in one ortho position and a methyl radical in the otner ortho position.
The above '945 patent contains some herbicidal data relative to those above-mentioned compounds having a chemical configuration most closely related to the invention compounds, and some data are presented for other homologous and analogous compounds less-closely related in chemical structure, e.g., said Compound Numbers 6 and 9 in said '763 patent. More particularly, these most relevant references, while disclosing herbicidal activity on a variety of weeds, do not disclose any data for any compounds which are shown to additionally and/or simultaneously control the hard-to-kill narrowleaf weeds, blackgrass, wild oats and downy brome and other weeds such as yellow foxtail, annual rye, barnyardgrass and crabgrass, although said Belgian '763 patent presents data showing good control of wild oats and undefined species of various other weeds in sugar beets. However, as will be shown herein, compounds according this invention possess unexpectedly superior properties as selective herbicides in sugarbeets vis-a-vis the homologous compounds of the prior art.
A further disadvantage of many prior art herbicides is limitation of their use in specified types of soil, i.e., while some herbicides are effective in soils having small amounts of organic matter, they are ineffective in other soils high in organic matter or vice-versa. It is, therefore, advantageous that a herbicide be useful in all types of soil ranging from light organic to heavy clay and muck.
Yet another disadvantage of some prior art herbicides is the lack of weed control persistence under heavy rainfall which results in leaching of the herbicide.
And, finally, a disadvantage in some herbicides is the necessity to adopt and maintain special handling procedures due to the toxic nature thereof. Hence, a further desideratum is that a herbcide be safe to handle.
It is, therefore, an object of this invention to provide a group of herbicidal compounds which overcome the above-mentioned disadvantages of the prior art and provide a multiplicity of advantages for a single group of herbicides.
It is an object of this invention to provide herbicides which selectively control various weeds, particularly annual grasses, including hard-to-kill narrowleaf weeds such as blackgrass, wild oats and downy brome and other annual grasses such as yellow foxtail, barnyardgrass, crabgrass and annual rye, particularly. in sugarbeets.
Still another object of this invention is the provision of herbicides which are effective over a wide range of soils, e.g., ranging from light-medium organic to heavy clay and muck.
Another object of this invention is the provision of herbicides which are resistant to leaching under heavy rainfall.
Finally, it is an advantage of the herbicides of this invention that they are safe and require no special handling procedures.
The above and other objects of the invention will become more apparent from the detailed description below.